1. Field of the Invention
This invention relates to a method and apparatus for carrying-out a chemical analysis on organic or inorganic compounds and substances, for instance in the field of pharmaceuticals and in all synthesis methods wherein microspecimens are to be chemically analyzed.
More specifically, this invention relates to a method and apparatus allowing to detect the presence of predetermined chemical elements, as C, N, H, S and O in the analyzed specimens, to obtain proportionality ratios between said elements and the percentage of each element within the whole specimen, as well as some indications to statistically determine elements or groups of elements that are present in the residue of the specimen molecule besides those specifically and individually detected.
2. Description of the Prior Art
The known prior art comprises analysis methods allowing the detection of the percentages of well defined chemical elements, usually the abovestated ones, within the whole specimen and then to obtain a so called "reduced formula", wherein the atomic ratios between said detected elements are given. The above-stated known methods always involve a weighing operation of the specimen to be analyzed, and then a series of chemical treatments on said specimen in order to determine and detect the presence of said elements. The apparatus gives an out-put curve having a sequence of peaks, each relating to a given element. This curve allows the obtaining of the desired results by calculating the areas as defined by each peak above a given "ground" level and correlating the value of each area with the specimen weight and with an experimental factor in order to obtain the percentage of the corresponding element in the analyzed specimen. In other words, for each chemical element, there is previously determined an experimental factor by which the following parameters are correlated: specimen weight, percentage of the element in the specimen and area of the related peak. Such factor is obtained by means of an analysis carried-out, under the same conditions, on standard specimens containing known element percentages. Thereafter, the analysis may be repeated on an unknown specimen and said factors are used in order to calculate the percentage of each element within said specimen.
However, such known systems show certain drawbacks that are avoided according to the present invention.
In particular, such known systems always require a previous weighing operation of the specimen to be analyzed, said operation involving a considerable loss of time, requiring highly qualified operators, introducing possible errors and resulting in an impossibility in some instances, for example when specimens having volatile substances are to be analyzed. Further, said known systems do not allow exploitation of the weighing operation in order to obtain further elements from the analysis and in particular to obtain a statistic location of the molecule portion not directly analyzed and detected.